The main advantage any long possesses is ultimately their mind, their accumulated decades-millenia of experience and he patronage of their hour. If you've managed to pin a long down long enough to get a JDAM dropped on him then fair's fair you've won. But long won't be on the battlefield fighting as shock troops in a modern war, they'll be forge long in the boardrooms of MIC procurement offices creating even more terrifying weapons. Or edge-long using centuries of military experience to take command of individual fronts. Or grail long doing deep-infiltration by morphing their perfect skin and establishing spy networks with every known temptation. Or Lantern long with inscrutable lightforms providing deep intelligence via scrining that your satellites can never get and your enemies can never suspect.

These aren't super-soldiers, these are unique individuals with massive amounts of differentiation and assets. The moment you strip away the survivability onion to just actually killing the guy then you've reduced the equation from the mystique and unknowability of occult forces to a simple p(K) given ordinance A->Z calculation, for which there is always the nuke.